On January 29th, illustrator and reporter Susie Cagle accompanied a group of volunteers as they stalked the streets of San Francisco in an effort to quantify the city’s homeless population. San Francisco suffers from some of the worst economic inequality in the United States, and, as in other cities, services for its homeless residents are dependent on federally-mandated census taking. The problem is, the work of “counting” the city’s homeless is more imperfect than it might seem. Cagle’s dispatch, below.

Susie Cagle is a journalist and illustrator based in Oakland, California. She tweets at @susie_c